surface: process offset request without a buffer change

src/it/tests/t0020_surface_offset.rs

@@ -0,0 +1,55 @@
+use {
+    crate::{
+        it::{
+            test_error::TestError,
+            test_utils::{
+                test_container_node_ext::TestContainerExt, test_ouput_node_ext::TestOutputNodeExt,
+                test_toplevel_node_ext::TestToplevelNodeExt,
+                test_workspace_node_ext::TestWorkspaceNodeExt,
+            },
+            testrun::TestRun,
+        },
+        theme::Color,
+    },
+    std::rc::Rc,
+};
+
+testcase!();
+
+async fn test(run: Rc<TestRun>) -> Result<(), TestError> {
+    let ds = run.create_default_setup().await?;
+
+    let client = run.create_client().await?;
+    let seat = client.get_default_seat().await?;
+    let enter = seat.pointer.enter.expect()?;
+    let win1 = client.create_window().await?;
+    win1.map2().await?;
+
+    let buffer = client.spbm.create_buffer(Color::from_rgb(255, 0, 0))?;
+    let surface = client.comp.create_surface().await?;
+    let vp = client.viewporter.get_viewport(&surface)?;
+    vp.set_destination(100, 100)?;
+    surface.attach(buffer.id)?;
+    surface.commit()?;
+
+    let (x, y) = ds
+        .output
+        .workspace()?
+        .container()?
+        .first_toplevel()?
+        .center();
+    ds.move_to(x, y);
+
+    client.sync().await;
+    let enter = enter.next()?;
+    seat.pointer.set_cursor(enter.serial, &surface, 0, 0)?;
+
+    client.compare_screenshot("1").await?;
+
+    surface.offset(-100, -100)?;
+    surface.commit()?;
+
+    client.compare_screenshot("2").await?;
+
+    Ok(())
+}